A multinational assessment of complications in type 1 diabetes: the DiaMond substudy of complications (DiaComp) level 1

Sex differences in micro- and macro-vascular complications of diabetes mellitus

Vascular complications are a leading cause of morbidity and mortality in both men and women with type 1 (T1DM) or type 2 (T2DM) diabetes mellitus, however the prevalence, progression and pathophysiology of both microvascular (nephropathy, neuropathy and retinopathy) and macrovascular [coronary heart disease (CHD), myocardial infarction, peripheral arterial disease (PAD) and stroke] disease are different in the two sexes. In general, men appear to be at a higher risk for diabetic microvascular complications, while the consequences of macrovascular complications may be greater in women. Interestingly, in the absence of diabetes, women have a far lower risk of either micro- or macro-vascular disease compared with men for much of their lifespan. Thus, the presence of diabetes confers greater risk for vascular complications in women compared with men and some of the potential reasons, including contribution of sex hormones and sex-specific risk factors are discussed in this review. There is a growing body of evidence that sex hormones play an important role in the regulation of cardiovascular function. While estrogens are generally considered to be cardioprotective and androgens detrimental to cardiovascular health, recent findings challenge these assumptions and demonstrate diversity and complexity of sex hormone action on target tissues, especially in the setting of diabetes. While some progress has been made toward understanding the underlying mechanisms of sex differences in the pathophysiology of diabetic vascular complications, many questions and controversies remain. Future research leading to understanding of these mechanisms may contribute to personalized- and sex-specific treatment for diabetic micro- and macro-vascular disease.

Glucose control in Rwandan youth with type 1 diabetes following establishment of systematic, HbA1c based, care and education

AIMS

To assess change in glycemic control concurrent with increased clinic visits, HbA1c testing, and education. Rates of complications were also examined.

METHODS

A 1-2 year follow-up of 214 members of the Rwanda Life for a Child program (aged <26 years) with a first HbA1c between June 2009 and November 2010 was conducted. Data were analyzed for the entire cohort and by age (<18 years, ≥18 years). Trajectory analysis was performed to identify trends in HbA1c.

RESULTS

Mean overall HbA1c decreased significantly from baseline (11.2 ± 2.7%; 99 ± 30 mmol/mol) to one- (10.2 ± 2.6%; 88 ± 28 mmol/mol) and two- (9.8 ± 26%; 84 ± 25 mmol/mol) year follow up visits. The prevalence of microalbuminuria did not significantly change (21.0%, 18.8%, and 19.6%), nor did nephropathy (4.7%, 7.8%, and 5.4%). However, rates of hypertension (31.8%, 44.9%, and 40.3%) were higher than expected. Five HbA1c groups were identified by trajectory analysis, and those with the worst control monitored their glucose significantly fewer times per week.

CONCLUSIONS

The establishment of regular care, HbA1c testing, and increased education is associated with significant improvements in glycemic control in youth with type 1 diabetes (T1D) in sub-Saharan Africa, but the high prevalence of hypertension is of concern.

Male-female differences in diabetic retinopathy?

The purpose of this paper is to review male-female differences in the incidence and prevalence of diabetes and diabetic retinopathy. These differences will be established primarily through results from our present research and a review of related literature. Previously, we have demonstrated that neuroretinal dysfunction can be used to predict the location of future retinopathy up to three years before it is manifest. Our current research suggests that, for type 2 diabetes, the normal differences in neuroretinal function between nondiabetic males and females under 50 years of age are altered in patients with type 2 diabetes. Furthermore, local neuroretinal function in type 2 diabetes is more abnormal in adult males compared with adult females. The literature also suggests that there are male-female differences in the occurrence of diabetes. In adolescence, the incidence of type 1 diabetes is greater in males, whereas in type 2 diabetes, the incidence is greater in females. This excess of females in type 2 diabetes shifts to a more equal incidence between the two sexes in adults. In addition, advanced retinopathy in type 1 diabetes appears to be more common in males, and the presence and severity of diabetic retinopathy at the time of diagnosis in type 2 diabetes appears to be more associated with male sex. Although the reasons for male-female differences identified in this review are unknown, sex appears to be a significant factor in certain aspects of diabetes incidence and diabetic retinopathy.

Prevalence of diabetic retinopathy in various ethnic groups: a worldwide perspective

The alarming rise in diabetes prevalence is a global public health and economic problem. Diabetic retinopathy is the most common complication of diabetes and the leading cause of blindness among working-age populations in the Western world. Screening and prompt treatment of diabetic retinopathy are not top priorities in many regions of the world, because the impacts of other causes of preventable blindness remain an issue. Ethnicity is a complex, independent risk factor for diabetic retinopathy. Observations from white populations cannot be extrapolated fully to other ethnic groups. The prevalence of diabetic retinopathy, sight-threatening diabetic retinopathy, and clinically significant macular edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the white population. Although all ethnic groups are susceptible to the established risk factors of diabetic retinopathy-such as length of exposure and severity of hyperglycemia, hypertension, and hyperlipidemia-ethnic-specific risk factors also may influence these rates. Such risk factors may include differential susceptibility to conventional risk factors, insulin resistance, differences in anthropometric measurements, truncal obesity, urbanization, variations in access to healthcare systems, genetic susceptibility, and epigenetics. The rates of nonproliferative diabetic retinopathy appear to be declining in the United States, supporting the observation that better medical management of diabetes and prompt treatment of sight-threatening diabetic retinopathy substantially improve the long-term diabetic retinopathy incidence; studies from other parts of the world are limited and do not mirror this finding, however. We examine the ethnicity and region-based prevalence of diabetic retinopathy around the world and highlight the need to reinforce ethnicity-based screening and treatment thresholds in diabetic retinopathy.

Fatores socioeconômicos, demográficos, nutricionais e de atividade física no controle glicêmico de adolescentes portadores de diabetes melito tipo 1

OBJETIVO: Identificar a associação de condições socioeconômicas, demográficas, nutricionais e de atividade física sobre o controle glicêmico de adolescentes portadores de DM1. SUJEITOS E MÉTODOS: Estudo transversal com 71 adolescentes com diagnóstico clínico de diabetes tipo 1. Foram obtidos dados socioeconômicos, demográficos e antropométricos. O controle glicêmico foi classificado pelo índice de hemoglobina glicada (A1C). Foram aplicados quatro recordatórios de 24 horas de consumo alimentar e de atividade física. RESULTADOS: A A1C foi inadequada para a maioria dos adolescentes. A menor escolaridade do cuidador influenciou para o controle glicêmico inadequado. Pacientes com menor dose de insulina apresentaram melhor controle glicêmico. A alimentação observada foi hipoglicídica e hiperlipídica. A maioria dos pacientes era sedentária. CONCLUSÃO: Fatores relacionados à educação, à insulina e à alimentação influenciaram no controle glicêmico.

Residual insulin production and pancreatic ß-cell turnover after 50 years of diabetes: Joslin Medalist Study

OBJECTIVE

To evaluate the extent of pancreatic β-cell function in a large number of insulin-dependent diabetic patients with a disease duration of 50 years or longer (Medalists).

RESEARCH DESIGN AND METHODS

Characterization of clinical and biochemical parameters and β-cell function of 411 Medalists with correlation with postmortem morphologic findings of 9 Medalists.

RESULTS

The Medalist cohort, with a mean ± SD disease duration and age of 56.2 ± 5.8 and 67.2 ± 7.5 years, respectively, has a clinical phenotype similar to type 1 diabetes (type 1 diabetes): mean ± SD onset at 11.0 ± 6.4 years, BMI at 26.0 ± 5.1 kg/m(2), insulin dose of 0.46 ± 0.2 u/kg, ∼94% positive for DR3 and/or DR4, and 29.5% positive for either IA2 or glutamic acid decarboxylase (GAD) autoantibodies. Random serum C-peptide levels showed that more than 67.4% of the participants had levels in the minimal (0.03-0.2 nmol/l) or sustained range (≥ 0.2 nmol/l). Parameters associated with higher random C-peptide were lower hemoglobin A1C, older age of onset, higher frequency of HLA DR3 genotype, and responsiveness to a mixed-meal tolerance test (MMTT). Over half of the Medalists with fasting C-peptide > 0.17 nmol/l responded in MMTT by a twofold or greater rise over the course of the test compared to fasting. Postmortem examination of pancreases from nine Medalists showed that all had insulin+ β-cells with some positive for TUNEL staining, indicating apoptosis.

CONCLUSIONS

Demonstration of persistence and function of insulin-producing pancreatic cells suggests the possibility of a steady state of turnover in which stimuli to enhance endogenous β cells could be a viable therapeutic approach in a significant number of patients with type 1 diabetes, even for those with chronic duration.

Modern-day clinical course of type 1 diabetes mellitus after 30 years' duration: the diabetes control and complications trial/epidemiology of diabetes interventions and complications and Pittsburgh epidemiology of diabetes complications experience (1983-2005)

BACKGROUND

Clinical treatment goals of type 1 diabetes mellitus (T1DM) have changed since the Diabetes Control and Complications Trial (DCCT) demonstrated reduced long-term complications with intensive diabetes therapy. There have been few longitudinal studies to describe the clinical course of T1DM in the age of intensive therapy. Our objective was to describe the current-day clinical course of T1DM.

METHODS

An analysis of the cumulative incidence of long-term complications was performed. The DCCT (1983-1993) assigned patients to conventional or intensive therapy. Since 1993, the DCCT has been observational, and intensive therapy was recommended for all patients. The Pittsburgh Epidemiology of Diabetes Complications (EDC) study is an observational study of patients with T1DM from Allegheny County, Pennsylvania. The study population comprised the DCCT T1DM cohort (N = 1441) and a subset of the EDC cohort (n = 161) selected to match DCCT entry criteria. In the DCCT, intensive therapy aimed for a near-normal glycemic level with 3 or more daily insulin injections or an insulin pump. Conventional therapy, with 1 to 2 daily insulin injections, was not designed to achieve specific glycemic targets. Main outcome measures included the incidences of proliferative retinopathy, nephropathy (albumin excretion rate >300 mg/24 h, creatinine level >or=2 mg/dL [to convert to micromoles per liter, multiply by 88.4], or renal replacement), and cardiovascular disease.

RESULTS

After 30 years of diabetes, the cumulative incidences of proliferative retinopathy, nephropathy, and cardiovascular disease were 50%, 25%, and 14%, respectively, in the DCCT conventional treatment group, and 47%, 17%, and 14%, respectively, in the EDC cohort. The DCCT intensive therapy group had substantially lower cumulative incidences (21%, 9%, and 9%) and fewer than 1% became blind, required kidney replacement, or had an amputation because of diabetes during that time.

CONCLUSION

The frequencies of serious complications in patients with T1DM, especially when treated intensively, are lower than that reported historically.